Twist transmission device for a ring spinning apparatus

ABSTRACT

Twist transmission device for carrying out migration of twists to the upstream yarn between the yarn guide and the nip point of the front rollers. The device comprises a cap secured to a spindle head or bobbin head, and a follower supported by a bracket. The cap and the follower are provided with a permanent magnet respectively, and each comprises a plurality of North and South pole magnetized portions alternately arranged. The magnet of the follower is provided with a yarn guide. And the yarn guide is forced to rotate in synchronous condition with the rotation of the spindle by magnetic attraction between the permanent magnets of the cap and follower.

United States Patent 1191 Misaki June 4, 1974 .TWIST TRANSMISSION DEVICE FOR A 3,681,909 8/1972 Korikovsky et al. 57/l06 RING SPINNING APPARATUS 3,727,394 4/1973 Greive 57/106 Inosuke Misaki, Osaka, Japan Nitto Shoji Limited, Osaka-shi, Osaka, Japan Filed: Aug. 27, 1973 Appl. No.:'39l,62l

Inventor:

Assignee:

Foreign Application Priority Data Aug. 30, 1972 Japan..., 47-88l60 References Cited 7 UNITED STATES PATENTS l/l962 Kooistra et a1. ,L...-. 57/73 lO/l963 Kooistra 1. 57/73 v Primary Examiner-John Petrakes [5 7 1" ABSTRACT ,Twist transmission device for carrying out migration of twists to the upstream yarn between the yarn guide and the nip point of the front rollers. The device comthe follower are provided with a permanent magnet respectively, and each comprises a plurality of North 7 and South pole magnetized portions alternately ar- 1 ranged. The magnet of the follower is provided with a yarn guide. And the yarn guide is forced to rotate in synchronous condition with the rotation of the spindle by magnetic attraction between the permanent magnets of the cap and follower.

5 Claims, 10 Drawing Figures PATENTEDJUH M974 sum 1 of 3 PATENTEDJUM 41914 SKU31UF3 ITIIIQ N i f TWIST TRANSMISSION DEVICE FOR A RING SPINNING APPARATUS SUMMARY on THE INVENTION The present invention relates to a twist transmission device for a ring spinning unit, and more particularly relates to a device for transmitting twists of yarn to a nip point of a pair of front rollers of a ring spinning unit.

According to our experience, it has been well known that, in the conventional ring spinning system, a continuous bundle of fibers, which is continuously delivered from a draft mechanism, is twisted by a traveller running along a ring while a twisted continuous bundle of fibers is wound on a bobbin which is rotated with a spindle supporting the bobbin. (The above-mentioned continuous bundle of fibers is hereinafter referred to as a yarn.) In this twisting and winding operation, the twists are mainly concentrated at'a point where the yarn contacts a snail wire which guides the yarn delivered from the drafting mechanism, and a certain part of the twists is transmitted to a position adjacent to a nip point'of a pair of front rollers of the drafting mechanism. The above-mentioned transmission of twist is hereinafter referred to as migration of twist beyond the snail wire. On the other hand, a tension is imparted to the yarn in a zone between the nip point of the front rollers and the bobbin. This tension is created by running the traveller along the ring and forming a ballooning of the yarn about the bobbin in a position between the snail wire and the traveller. It has been also well known that the above-mentioned yarn tension varies duringthe spinning operation. This variation of yarn tension is due to the changes of package size, position of ring according to the lifting motion of a ring rail mounting rings, driving speed of the spindle, etc. If a weak point of the yarn cannot bear the abovementioned tension, then the yarn is broken. Many attempts have been made to prevent such yarn breakage 'during the spinning operation of the conventional ring spinning system, and some of these attempts have been practically applied. However, in spite of these practical attempts, such as a system for controlling the driving speed of the spindle, and application of a balloon control device, there is a certain upper limit in the driving speed of the spindle. This upper limit depends upon the spinning material, yarn count, and number of twists imparted to the yarn.

According to our experience, the above-mentioned yarn breakage occurs most in a zone between the snail wire and the nip point of the front rollers, because most of the desired twists are imparted to the yarn in this a zone. The above-mentioned zone is hereinafter referred to as an upstream yarn portion. Although not confirmed it is understood that several attempts have been made to positively transmit the twist to the upstream yarn portion beyond the snail wire. However,

these attempts failed because of the requirement for complicated mechanisms which cannot be utilized in practice.

The principal object of the present invention is to solve the above-mentioned problem observed in the migration of twist beyond the snail wire, in other words, to provide a practical device for transmitting twist to a position adjacent to the nip point of the front rollers so that the yarn breakage during'the spinning operation can be prevented and consequently the driving speed of the spindle can be elevated. I

In the device for transmitting twists to the upstream yarn portion beyond the snail wire according to the,

present invention, a yarn guide having a particular construction is utilized instead of the conventionalsnail wire. This yarn guide comprises a trumpet shaped guide member and a permanent magnet composed of a plurality of North and South pole magnetized portions which are arranged alternately outside the guide member in a symmetrical condition, and a cylindrical case rigidly holding the above-mentioned permanent magnet, a horizontal ball bearing rotatably holding the cylindrical case and a member for supporting the horizontal ball bearing at an adjacent position above the tip of the spindle head. In the above-mentioned construction of the yarn guide, the guide memberis preferably secured to the cylindrical case. A cap provided with a permanent magnet, composed of a plurality of magnetized portions, is mounted on the spindle or bobbin in such a way that the distance between the cap and the permanent magnet attached to the yarnv guide is so close that a magnetic-flux is created therethrough, and the permanent magnet of the yarn guide is forced to follow the rotation of the cap so that the guide member is rotated at a speed similar to the cap. Consequently a larger number of twists then the predetermined yarn twist is imparted to the upstream yarn portion. Becuase of this imparting of twists to the upstream yarn, the yarn is strengthened in this zone. Even if an excess number of twists is imparted in the upstream yarn porinvention will be hereinafter illustrated in more detail with reference to the embodiments lowing drawings' BRIEF ILLUSTRATION OF THE DRAWINGS FIG. 1 is a schematic side view of a spinning unit utilizing the, device according to the present invention;

FIG. 2 is' an enlarged cross sectional view, taken along a longitudinal axis of the device shown in FIG. 1;

shown in the fol- FIG. 3 is a cross sectional view of the device, taken I along the line III III in FIG. 2;

FIG. 4 is a cross sectional vieWQtaken along the line IV IV in FIG. 2;

FIG. 5 is a longitudinal cross sectional view of another embodiment of the cap according to the present invention; u

FIG. dis a longitudinal cross sectional view of another embodiment of the follower according to the present invention;

FIG. 7 is a cross sectional view of the follower taken along the line VI VI in FIG. 5, and;

FIGS. 8A, 8B, 8C are explanatory diagrams showing the function of the device shown in FIG. 6;

DETAILED EXPLANATION OF THE INVENTION Referring to FIGS. 1, 2, 3 and 4, the twist transmission device of the ring spinning apparatus according to the present invention comprises a cap member 1 rigidly mounted on a tip of a spindle 2, and a follower 3 rotatably held by a supporting bracket 5 at a position adjacently above the cap member 1. The cap member 1 comprises a cylindrical base element 6 rigidly secured to the tip portion of the spindle 2 by a horizontal pin 7 which passes therethrough, a hollow cylindrical head 8 mounted on the cylindrical base element 6 by thread engagement, and a permanent magnet 9 disposed inside the hollow cylindrical head 8. The outside diameters of the cylindrical base element 6 and the hollow cylindrical head 8 are identical and they coincide with the diameter of the cylindrical hollow inside wall of the tip portion of a bobbin 111 so as to stably support the tip portion of the bobbin 10. The cylindrical base element 6 is provided with a helical thread 6a formed at the top outside .surface thereof while the hollow cylindrical head 8 is provided with a helical thread 8a formed at an inside wall of the skirt portion thereof and these helical threads engage each other. The hollow cylindrical head 8 is further provided with an inside cylindrical wall 8b which defines a doughnut shaped area therein. The above-mentioned permanent magnet 9 is inserted into this doughnut shaped area as shown in FIG. 2. To hold the permanent magnet 9 at a predetermined position a ring shaped rib 6b is formed at the top surface of the cylindrical element6 and a yoke 11 is inserted between the magnet 9 and the ring shaped rib 6b. The

magnet 9 is magnetized so as to form a plurality of North and South pole magnetized portions radially and alternatel arranged.

Thefollbwer 3 comprises: a ring shapedcasing 12, provided with a cylindrical wall portion 12a and a central aperture 1217; an outside casing 13 provided with a cylindrical top portion 13a, a cylindrical bottom portion 13!) and an intermediate portion 130 which connects the cylindrical top portion 13a to the cylindrical bottom portion 13b;v a trumpet shaped inner casing 14, provided with a ring shaped bottom flange 1 1a; a ball bearing 15 rigidly held. by the cylindrical wall portion 120 ofthe casing 12 in such a way that an outer ring 1517 thereof is rigidly held; a permanent magnet 16 rigidly held in a doughnut shaped area formed between the cylindrical bottom portion 13b and the inner casing 14 when the above-mentioned elements of the follower 3 are assembled and a filling substance such as a plastic resin is filled in a space formed between the intermediate portion l3c of the outside casing 13 and the permanent magnet 16 and the inner casing 14; a conical cylindrical member 17 provided with a top flange 17a which is secured into the top cylindrical portion 130 of the outside casing 13; a plastic guide member 18 rigidly inserted into the central aperture of the conical cylindrical member 17, and; a ring shaped yoke 19 disposed upon the permanent magnet 16. After completion of the assembly of the elements of the follower, the ring shaped casing 12 is rigidly held by 'the horizontal bracket 5 as shown in FIG. 2. When the abovementioned elements are assembled, the outside casing 13 is firstly assembled with an inner ring 15a of the ball bearing 15 in such a way that the top cylindrical portion 13a of the outside casing 13 is rigidly held by the inner ring 15a, next the permanent magnet 16, the yoke 19, the plastic filling 20 and the trumpet shaped inner casing 14 are assembled. In this condition, the edge of the flange 14a is rigidly held by the bottomedge portion of the cylindrical bottom portion 13b of the outside casing 13. Then the conical cylindrical member 17 is rigidly inserted into a space between the top cylindrical portion 13a of the outside casing 13 and the top portion of the trumpet shaped inner casing 14. By the above-mentioned construction of the, follower 3, the permanent magnet 16 and the plastic guide member 18 are capable of turning with the inner ring 150 of the ball bearing 15, while the outer ring 15b is rigidly held by the cylindrical wall portion 12a of the casing 12.

The permanent magnet 16 is magnetized so as to form a plurality of North pole and South pole magnetized portions radially and alternately arranged as shown jn IiIGS. 3 and 4. In the above-mentioned assen bTy of the ranswe'rsja nan-magnate matefiai' such as stainless steel is utilized for making the elements 12, 13, 14, 17. This type of non-magnetic material is also utilized for making the elements 6, 7 and 8 in the cap 1.

In mill operation, a yarn 21 delivered from the nip point 22 of the front rollers 23, 24 is carried to the guide member 18,-and then carried to a traveller 32 running along a ring 33. If the distance between the permanent magnet 9, which rotates with the spindle 2 at a very high speed, and the permanent magnet 16 is sufficiently small to create magnetic flux passing through a magnetic segment of the permanent magnet 9 and a magnetic segment of the pennanent magnet 16, the permanent magnet 16 is forced to follow the rotation of the permanent magnet 9 of the cap 1. Consequently, in such a case the permanent magnet 16 is forced to rotate about the central axis of the ball bearing at a speed similar to the spindle 2.

As the yarn 21 contacts the yarn guide 18 under tension, twist is imparted to the yarn between the yarn guide 18 and the nip point 22 of the front rollers 23, 24. According to our experience with the conventional ring twister, about percent of the twists imparted to the yarn in a zone between the snail wire and the traveller are mig rated to t hfiarrfin the zone between the snail wire and the nip point of the front rollers I-Iowever, according to the present invention, theyam guide is rotated at a speed similar to the spindle, and an excess twist is imparted to the yarn between the yarn guide 18 and the nip point 22 of the front rollers 23, 24. In other words, besides the abovementioned migration of twists to the upstream yearn beyond the yarn guide 18, certain excess twists are imparted to the upstream yearn. Consequently, the twisting point on the upstream yarn, where the twist is concentrated, can be displaced closer to the nip point 22 'of thefro nt'rollers 23,24: According to the above-mentioned excess twist and displacement of the twisting point toward the nip point 22, the yarn strength in this upstream position is elevated and the yarn surface becomes smooth because oftlie remark able elimination of naps projected from the yarn body. Based on our mill tests, the number of twists of the produced yarn is identical to that of-yam produced by the conventional ring twister. Consequently,it is our inter pretation that, even if a' large excess of twists are imparted to the upstream yarn, the excess twists over the twists created in the downstream position, that is, in a zone between the yarn guide 18 and the traveller 22, is eliminated when the upstream yarn'passes through the yarn guide 18 in a somewhatsimilar manner to false twisting. 1

In the above-mentioned embodiment, the yarn guide 18 is provided with a smooth surface for guiding the yarn 21. However, it is also useful to provide a rough surface having a higher coefficient of friction or having sharp edges. 7

According to our repeated mill tests in a worsted spinning mill, it was confirmed that yarn breakage is remarkably decreased, while the yarn qualities such as variation of thickness, and breaking strength of yarn are identical to the conventional yarn. For example, in

'the spinning test of 1/86 worsted yarn (spindle-speed 7,000 rpm), the yarn breakage per 400 spindle hours was less than 20, while that of a conventional spinning unit is about 50, and; the variation of twist distribution along the yarn (coefficient of variation) was 23.5 with the present invention, while that of the conventional spinning unit was 25.9. Consequently, it was confirmed that the twist distribution along the yarn can be remarkably improved. r

In the above-mentioned embodiment, the carrier 1 is rigidly mounted to the tip portion of the spindle 2. However, it is also useful to mount the cap to the tip portion of the bobbin as shown in FIG. 5. In this embodiment, the permanent magnet 9 is covered with an upper casing 25 and a lower casing 26, an insert 27 is rigidly inserted into the tip of the bobbin l0, and the assembly of the casings 25, 26 with the permanent magnet 9 is also rigidly mounted on a tip portion of the insert 27.

According to our research, if a brake action acts on the follower, the axial positions of the poles of the permanent magnet 16 coincide with the permanent magnet 9. In this .condition, the magnetic flux between the permanent magnets 9 and 16 is eliminated so that the rotation of the follower 3 is stopped. In this condition, the migration of twists to the upstream yarn is carried out as with the conventional ring twister. Consequently, it is necessary to stop the running of, the spindle so as to adjust the relative axial positions of .the poles of the permanent magnets 9 to those of the permanent magnet 16 manually, so as to restart the running of the follower 3. This operation is troublesome. The embodiment shown in FIG. 6 is constructed so-as to avoid the above-mentioned troublesome manual operation. For the sake of easy understanding, the above-mentioned phenomenon will first be analyzed.

It is assumed that the permanent magnets'9 and 16 are composed of four poles, respectively, that is, each permanent magnet is provided with two North pole portionsand two Southpole portions arranged alternately. The relative positions of these portions are shown in FIGS. 8A, 8B and 8C. InFIG. 8A, the North pole portions of the permanent magnet 16 face the South pole portions of the permanent magnet 9, while the South pole portions of the magnet 16 face the j North pole portions of the magnet 9. In this condition,

the rotation of the permanent magnet 16 synchronizes to the rotation of the permanent magnet 9, that is, the spindle 2. However, if the angular position of the permanent magnet 16 relative to the permanent magnet 9 is changed as shown in FIG. 8B, the high speed rotation 'of the spindle 2 cannot be followed by the follower 3 because of a certain braking action, and the abovementioned relative position .is finally changed to the condition shown in FIG. 8C. In this condition, the magnetic flux passes through two adjacent North and South pole portions of the permanent magnet 9, and the permanent magnet 16 respectively .50 that these two permanent magnets 9 and 16 repel each other and the follower 3 is stopped. However, if a magnetic metallic substance is disposed on either one of the permanent magnets 9 or 16, even in the condition shown in FIG.

The embodiments shown in FIG S: 6, 7 are designedon the basis of the above-mentioned idea. An outside ring 31 is concentrically disposed outside the outside casing 13 at a level which corresponds to the upper portion of the permanent magnet 16. To hold this outside ring 31, a plurality of magnetic portions 30 are rigidly inserted .into the space between the outside ring 31 and the outside casing 13 as shown in these drawings. These magnetic portions work to weaken the repelling force in the condition shown in FIG. 8C. In the embodiment shown in FIGS. 6 and 7, the elements having the same function as the elements shown in FIG. 2 are designated by identical reference numerals, and any illustration thereof is omitted.

In the embodiments shown in FIGS. 6 and 7, a plurality of magnetic portions-30 are utilized. However, it is also applicable to utilize a ring shaped magnetic por tion instead of the above-mentioned separated magnetic portion 30.

According to our experience, it is also practical to rigidly dispose a magnetic material upon the top portion of the hollow cylindrical head 8 of the cap, instead of utilizing the magnetic material 30 with the follower As already explained in detail, the twist transmission device according to the present invention is a very useful device for decreasing yarn break in the ring twist apparatus. Therefore, it will be understood that, in a spinning process wherein yarn is frequently broken, the present twist transmission device is very useful to decrease or eliminate frequent yarn breakage. Beside reducing yarn breakage, the yarn quality can be remarkably'improved. For example, in the worsted spinning process for producing fine countyam, the remarkable decrease of yarn breakage introduces a remarkable decrease in the number of knotting portions so that yarn of high quality can be produced. As mentioned above, the present twist transmission device for the ring twisting assembly is a very unique and useful device in the spinning mill. i

What is claimed is:

I. In a ring twisting assembly provided with a yarn I guide, ring and spindle, and a traveller running along said ring, a bracket for'supporting said yarn guide, a device for transmitting twists to an upstream yarn portion beyond said yarn guide, comprising a cap rigidly mounted on a tip portion of said spindle, a follower rotatably supported by said bracket at a position adja cently above said cap in a condition having a common longitudinal axial line with said cap, said cap provided with a permanent magnet composed of plural magnetized portions of North or South polarity radially arranged around said axial line in alternate disposition;

8 axial line; said yarn guide being rigidly inserted into said cylindrical casing assembly.

2. A twist transmission device according to claim 1, further comprising at least onemagnetic material disposed adjacent to said follower at symmetric radial positions outside said second permanent magnet.

3. A twist transmission deviceaccording t o claim 1,

wherein said second permanent magnet of said follower is disposed below said ball bearing a I 4. A twist transmission device according to claim 1, wherein said cylindrical casing assembly of said follower is made of non-magnetic material,

5. A twist transmission device according to claim 1, further comprising at least one magnetic material disposed at a position adjacent to said second permanent magnet of said follower.

V l= V Niki 

1. In a ring twisting assembly provided with a yarn guide, ring and spindle, and a traveller running along said ring, a bracket for supporting said yarn guide, a device for transmitting twists to an upstream yarn portion beyond said yarn guide, comprising a cap rigidly mounted on a tip portion of said spindle, a follower rotatably supported by said bracket at a position adjacently above said cap in a condition having a common longitudinal axial line with said cap, said cap provided with a permanent magnet composed of plural magnetized portions of North or South polarity radially arranged around said axial line in alternate disposition; said follower comprising a ball bearing having an outer ring, an inner ring and a plurality of balls disposed between said outer ring and inner ring, a cylindrical casing assembly provided with a doughnut shaped recess concentrically formed therein about the axis of said ball bearing and rigidly supported by said inner ring, and a permanent magnet disposed in said doughnut shaped recess and composed of the same number of magnetized portions of North or South polarity radially arranged in alternate disposition about said common axial line; said yarn guide being rigidly inserted into said cylindrical casing assembly.
 2. A twist transmission device according to claim 1, further comprising at least one magnetic material disposed adjacent to said follower at symmetric radial positions outside said permanent magnet.
 3. A twist transmission device according to claim 1, wherein said permanent magnet of said follower is disposed below said ball bearing.
 4. A twist transmission device according to claim 1, wherein said cylindrical casing assembly of said follower is made of non-magnetic material.
 5. A twist transmission device according to claim 1, further comprising at least one magnetic material disposed at a position adjacent to said permanent magnet of said follower. 